Recently, organic light-emitting elements have become markedly advanced. Features of organic light-emitting elements include the high luminance achieved by a low applied voltage, a variety of emission wavelengths, a high-speed responsiveness, and the possibility of realization of a thin, lightweight light-emitting device. Accordingly, the possibility of a wide variety of applications has been suggested for organic light-emitting elements.
However, under the present situation, an optical output with a higher luminance and higher conversion efficiency are necessary. Furthermore, there are still a lot of problems in terms of durability, for example, a change with time due to long-term use and degradation due to an atmospheric gas containing oxygen, moisture, or the like. Furthermore, considering the application to a full-color display or the like, light emission of blue, green, and red having good color purity is necessary, but technologies related to these issues have not yet satisfactorily been developed.
A large number of aromatic compounds and fused-ring aromatic compounds have been studied as fluorescent organic compounds used as an electron-transporting layer, a light-emitting layer, or the like. However, compounds having satisfactorily high light-emission luminance and durability have not yet been developed.
Fused-ring aromatic compounds have been investigated in various fields, and Non Patent Citation 1 has reported the carcinogenic potential and reactivity of such compounds.
Furthermore, Patent Citations 1 to 4 disclose examples in which an aromatic compound or a fused-ring aromatic compound is used as a material constituting an organic light-emitting element. Patent Citations 1 to 4 disclose an application of fused polycyclic materials to organic light-emitting elements.
Non Patent Citation 1
    Journal of Molecular Structure, 362, 29-49 (1996)Patent Citation 1    Japanese Patent Laid-Open No. 2002-8867Patent Citation 2    Japanese Patent Laid-Open No. 10-330295Patent Citation 3    Japanese Patent Laid-Open No. 10-294177Patent Citation 4    Japanese Patent Laid-Open No. 2005-53806